The retina disease known as macular degeneration causes an absence of central vision in the patient's eye due to a deficiency of the central retinal portion. In order to restore a certain amount of useful vision to the patient, it is necessary to greatly magnify the object at which the patient looks. This can be accomplished to some degree by eyeglasses, magnifiers or telescopes; however, several problems exist.
Spectacle glasses must have quite high power for sufficient magnification (up to +20D). Problems with spectacle magnifiers are (1) short working distance (only 8.3 cm for 3.times. magnification; and (2) weight and fitting the separation between the spectacle and the eye must be exact. Magnifiers have a very restricted visual field (a 3.times. magnifier of 5 cm diameter has about a 3 cm viewing field). They also have a short working distance and are inconvenient to use. Telescopes are used for distant object viewing and consequently have a long working distance. They must be light-weight and have a very restrictive visual field (less than 20 degrees at 2.times. magnification, and down to 4 degrees at high magnification, as compared to a minimum field angle of 30.degree. required for comfortable vision). Koester, C. J., and Donn, A., International Pat. No. WO83/01566, disclose a telescope system as continuation of high power glasses (up to 30D) and high negative intraocular lens (down to -100D). This combination theoretically might give higher viewing field up to 30 degrees for 2.5.times. which is limited by spectacle glasses, as similar to spectacle magnifier. This arrangement is inconvenient to high power spectacles and even more restrictive in fitting (for +30 D spectacle variation in distance from the spectacle to the eye must be kept within 1 mm).